


My Favorite Body Part

by mountain_ash



Series: Fun with Physiology [1]
Category: Teen Wolf (TV)
Genre: Alternate Universe - College/University, Alternate Universe - Human, Awkward Derek, Fluff, Forbidden Love, One Shot, POV Stiles, Persistent Stiles Stilinski, Rebuilt Hale House, Stiles Wears Glasses, Student Stiles, Teacher Derek, Wolves, only temporarily
Language: English
Status: Completed
Published: 2015-10-03
Updated: 2015-10-03
Packaged: 2018-04-24 14:37:59
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,849
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4923436
Author URL: https://archiveofourown.org/users/mountain_ash/pseuds/mountain_ash
Summary: <blockquote class="userstuff">
              <p>Derek is an awkward physiology TA. Stiles gets perfect grades. He goes to Derek's insanely early weekly office hours anyway.</p>
            </blockquote>





	My Favorite Body Part

**Author's Note:**

> Based on my real life existence with a very cutely awkward TA who holds lab at a very inconvenient time.

Stiles had finally managed to get into physiology his senior year of college, thanks to desperate begging for the sake of his major in criminal anthropology. Berkeley allowed fifth-year students, but he couldn’t afford another year of tuition, even if it was in-state. Unfortunately, being a late addition to the course meant he’d been forced to accept a discussion section for early Monday morning, which was literally the worst. Who even was his TA that they would be so cruel?

Despite the early hour (7:30 AM!) he managed to trip into class five minutes early as always. Stiles was nothing if not punctual, because if he wasn't early, he was bound to lose track of time and never make it at all. He was unsurprised to find he was the first to arrive, even beating his TA, and he took the seat at the large oval table directly opposite the chalkboard. Six more students trickled in before 7:30, when finally an intimidating and beautiful man stepped in and shut the door.

Stiles did his best to contain the inappropriate moan of satisfaction that threatened to escape his throat at laying eyes on the TA. He was easily Stiles's height, but significantly more built, with pecs and shoulders that strained against a grey Henley. Dark scruff outlined a glorious jawline, and large equally dark eyebrows knit down over nervous looking pale green eyes.

The TA cleared his throat and Stiles was shaken from his aggressive staring. "Um, so you’re all here for Physiology discussion section 6 right?" The seven students gave various signals of affirmation and he continued. “Okay, uh, well I’m Derek Hale, your TA. There were some stragglers that got added to this class, so I got added last minute to the course staff for this discussion section. My phone number will be on the first handout. I don’t check my email in the morning, so if you’re going to be late or absent text me why before discussion starts. I’m a first year grad student in Professor Cullen’s evolutionary phys lab and my work is in comparative animal locomotion.”

“Yet you’re teaching human phys?” A skeptical looking red-head sitting next to Stiles piped up.

“Humans are animals too.” Came the curt response. Stiles couldn’t help but take pity on the poor guy who couldn’t seem to make eye contact with anyone. This was going to be an interesting semester. “Anyway, that’s enough about me. Going around the table say your name, year, major, and favorite body part. Nothing vulgar unless you can give a scientifically valid reason. You can start." He finished gruffly, nodding at the red-head.

She gave him a tight smile through pursed lips before introducing herself tersely. "Lydia Martin. Senior. Biomechanical engineering. Hair."

Derek nodded at the student in Lydia's other side to continue and Stiles silently cheered. He needed a good answer. Even he wasn’t above making the TA squirm a little.

After Lydia came Boyd, a junior majoring in kinesiology, a senior named Allison majoring in personal training, senior twins names Aiden and Ethan both majoring in biochemistry, and finally Scott, a senior doing pre-vet. Most of them had chosen pretty benign body parts, but Scott had chosen teeth which Stiles could appreciate as a little weird. Then it was his turn and he had the perfect answer.

"Uh, Stiles. Don't bother trying to pronounce the name on the roster. I'm a senior studying criminal anthropology." He directed what he hoped was a subtly playful glance up at Derek, who of course wasn’t looking, before finishing. "And my favorite body part is foreskin."

Derek made a choking noise that he tried to play off as clearing his throat before finally looking up and landing a glorious scowl on Stiles. "Y-you better have a good reason for that one." He stuttered out awkwardly.

Unleashing a shit-eating grin on the TA, Stiles took a breath before diving into his explanation. “Well, when I was in high school I wrote an essay on the history of the male circumcision, so I learned all sorts of cool stuff about foreskin. Even though scientists aren’t a hundred percent sure exactly what foreskin does for us, based on evolutionary studies they’re pretty sure it serves some purpose in facilitating emotional bonding between mates during sexual intercourse. Apparently vaginal secretions contain vasopressin which is something foreskin is pretty good at absorbing and that helps create a chemical bond between mates.” He paused before adding on a last side-note. “Also, it’s self-lubricating so if you add that to its mechanics, foreskin is basically designed to make sex better for both partners, and who doesn’t love that?” Stiles quirked an eyebrow at Derek, and the TA blinked quickly before clearing his throat again and nodding stiffly.

“Alright. Fascinating.” Derek turned around swiftly to grab a stack of papers from his bag on the floor and Stiles couldn’t help but ogle some more. If Derek’s pecs weren’t going to destroy Stiles’s focus this semester, his ass definitely was.

Discussion ended up being composed of Derek giving them worksheets of questions the professors had created to mimic tests. Each student was asked to answer one question on their own without notes and then the class would discuss whether or not the answer was right. Over the first couple sessions,  Stiles bonded with Scott, developed a friendly rivalry with Lydia, and was almost completely sure he had blown most of Derek's remaining gaskets with his attempts at flirting.

If he had expected the TA to be anything, it was cocky and self-assured, not majorly awkward and with limited people reading skills. When the curriculum demanded Derek lecture about something, he struggled to make eye contact with them and bumbled through the information like he didn't know quite what he was saying. Stiles knew Professor Cullen's reputation though, and she didn't take on research students who weren't basically brilliant in various aspects of physiology, so he decided he was going to figure out just how smart Derek was one way or another. If he flirted with him along the way, that was just a bonus.

Derek held office hours every Friday morning a half hour earlier than he held discussions, and it was a real testament to Stiles's interest that he was willing to brave the early hour just for the TA. Apparently no one else ever did because Derek's door was shut when he arrived, as though he knew no one would come. Perhaps that indeed was the point.

Stiles knocked hesitantly, suddenly a little unsure he had actually gotten the time right, but Derek's voice answered from the other side, "Come in," so he turned the knob and stepped in. Derek sat at his computer with his back turned and Stiles got a few moments to appreciate the beautiful back muscles that stretched through his red Henley before he turned around. Upon seeing Stiles, what had been an attempt at a welcoming expression turned into confusion and perhaps a little anxiety. "What're you doing here?"

Stiles shouldn't have cared so much, but the fact that the TA didn't want him there hurt his feelings more than he cared to admit. "Uh. Coming to your office hours?" He tried to sound nonchalant but it came out a little more lost puppy and he cringed inwardly for letting Derek get at his confidence so easily.

"But you don't need help." Derek still looked uneasy. "You get perfect scores and know all the answers in class."

Stiles blushed, actually blushed, at the praise. If he didn't know better he'd say his pants also got a little tighter too and he sat down quickly on the other side of Derek's desk before the situation got any more embarrassing. Apparently praise got him going a little more than he thought.

“Um, no I don’t. But I do like physiology, so I wanted to talk about your research.”

Derek looked absolutely flabbergasted before suddenly turning suspicious. “You know I’m not going to give you extra credit or anything right?”

Stiles mouth fell open at the ridiculousness. Was this guy really that jaded? Or maybe just that oblivious?

"Dude no! I'm not some grade grubber. I'm just an intellectually curious guy with an appreciation for the human body."

Derek looked more constipated by the second. "First off, don't call me dude. I'm technically your teacher. Second, why don't you go to Professor Cullen's hours considering it's actually her lab?"

What was this guy’s problem? Stiles recoiled back into his chair and scrubbed his hand across his 5-o’clock-shadow in discomfort. “Have I done something wrong?” He must have somehow managed to look even more offended than he felt because Derek suddenly looked repentant.

“Oh, no. I just don’t get why you want to be here.” The TA looked adorably confused as he said it, and Stiles was starting to realize that Derek didn’t suffer from arrogance. He suffered from lack of confidence.

Stiles smiled at Derek conspiratorily and leaned forward, resting his elbows on his knees. “You do realize the reputation Professor Cullen has for choosing grad students right?” Derek nodded tentatively, clearly unsure of where this was going. “So you do realize that I’m fully aware that your research is probably mind blowing right?” This time Derek just blinked his beautiful pale green eyes at Stiles in utter confusion.

“You woke up for 7:00 AM office hours just to get me to talk about my research?” Stiles nodded once emphatically. “I don’t like talking.”

“So I’ve gathered. But I’m going to keep coming every Friday until you do, so you might as well try.” Worried Derek would take the opportunity to ask him why again, Stiles stood quickly, grabbed, his backpack and sped to the door. “See you Monday!” He called behind him, looking back only briefly to see Derek raise a baffled hand in goodbye.

Derek spoke with a little more confidence on Monday, managing to blend his ideas into single, coherent thoughts. He even made a little eye contact, mostly, much to his deep pleasure, with Stiles.

On Friday he showed up again at Derek’s office as promised. The door was open this time, but Derek still started in surprise when Stiles knocked, like he couldn’t believe Stiles had actually come. “Oh, Stiles. Come in.”

Stiles dropped his messenger bag on the ground and flopped elegantly into the proffered chair. His stomach grumbled awkwardly loudly as he situated himself and he blushed a little at the intrusive noise. He may have spent more time than expected trying to actually make himself presentable that morning, and as a result run out of time to eat breakfast. Being hungry was worth it though, because dressed in fitted chinos, a deep red v-neck, and an unbuttoned heather gray cardigan, he looked particularly good this morning. He'd even worn his [glasses](http://www.ray-ban.com/usa/eyeglasses/RX5309-rb5309-green/8053672122640) to round out the look. 

Derek chuckled when he heard Stiles’s stomach, which only made his blush deepen. He’d finally managed to make Derek laugh and it wasn’t even because he was funny. “Skip breakfast?” Rubbing the back of his head sheepishly, Stiles nodded and Derek rummaged in a drawer for a second before pulling out a Nutrigrain bar. “Here. You can’t take in my mind blowing research on an empty stomach.”

Stiles felt his heart surge in his chest as he realized Derek was using his words from the week before and it suddenly hit him how much he legitimately liked Derek. He wasn't just trying to mess with him and see how much he could make him squirm anymore. Somehow during last week's office hours, Derek had thoroughly wiggled underneath his skin and now all he wanted was for him to like him back. Too bad Derek was a stickler for rules and dating would be totally against school policy, but Stiles was persistent and if he had to keep at Derek until he wasn't in his class anymore, he would.

"Thanks." He said warmly, accepting the food. "It's about all I can do getting here on time with my clothes on. Breakfast is definitely not an option."

Derek looked at him like he was an alien. "Yet you're still here."

"Yep! I want you to tell me about the gait patterns of wolves."

It was obvious he was hesitant to share, skimming over details and paraphrasing methods he was in the process of developing, and Stiles wanted to prod but he didn't. Instead he paid rapt attention and attempted to stifle his attention-deficit tendencies that would make it look like he wasn't interested in Derek's work. The last thing he wanted to do was ruin the tenuous confidence Derek was developing by looking bored.

When Derek finished, it occurred to Stiles that he hadn't answered the most important of all research questions. "So why do you study wolves anyway?"

A film of sadness glazed over Derek's eyes and Stiles immediately regretted asking. "You don't have to tell me. It's fine."

Derek shot him a small, grateful smile. "Y-yeah. Another time maybe."

“Okay, well I’ll see you next week then.” Stiles left the office more hesitantly than he had the week before.

On Monday, Derek smiled at him softly when he entered class and Stiles’s entire face turned blotchy and pink and Scott asked him if he was choking. Lydia smirked knowingly.

The door was not only shut on Friday, but locked and his heart plummeted unexpectedly painfully. Derek hadn’t said his hours were cancelled but maybe he’d gotten sick. Stiles considered just leaving but he decided to be brave and texted Derek instead. 

Stiles: Hey Derek. Did you cancel office hours this morning?

Derek: Hey Stiles. I’ll be there soon. Sorry I’m late.

An unreasonably giddy smile crept up Stiles’s cheeks knowing that Derek had known it was him without saying so, like he just assumed Stiles was the only student who would ever go to office hours. It grew wider when he heard Derek coming down the hall and saw a tray of coffees in one hand and a bag in the other, which he held out to Stiles as he neared him in the hall.

“Y-you brought me breakfast?” He managed to stutter out, pink threatening to take over his face again.

Derek raised an eyebrow judgmentally and raised a teasing warning finger. “I brought you donuts. Don’t get the two confused.”

Stiles stared at him in wonder for a moment before he realized his mouth was hanging open again and he figured he should say something. “Don’t worry. I had an apple, so that makes two-thirds of a balanced breakfast.” Feeling brave, he gave Derek a mischievous wink and the TA swallowed loudly before shuffling past him to unlock the door.

Stiles took several minutes to appreciate the variety of donuts Derek had gotten him, taking care to avoid the jelly filled one. Not missing Derek's aborted motion to grab it, Stiles pushed it towards him and made a Herculean effort not to swipe it away with his thumb when he got jelly on his chin.

"So what do you have for me today?" Derek finally asked once Stiles had gotten through his donuts.

"Actually I have some real questions about animal behavior today. Part of criminal anthropology is understanding what different animal attacks look like and in what kind of situations they occur. So we can distinguish animal events from human ones, you know? So I know wolves don’t really attack people much, but could you tell me about what happens when they do?”

Watching Derek talk about wolves was beautiful, Stiles decided. When he was tentatively describing his research the week before, Stiles had seen the academic side of him, carefully picking his words to craft the just-right description for his study. Now, even though he still seemed vaguely uncomfortable at being the center of Stiles’s attention, his face had a light to it as though he could just talk about wolves forever. Stiles was inclined to let him, but suddenly a knock came at the door and Derek’s head snapped towards the person standing there, leaving Stiles to realize they had been maintaining incredibly intense eye-contact for who knew how long.

The woman standing at the door was older than Derek, blonde, very pretty, and she seemed to make Derek quite uncomfortable.

“Professor Argent.” He said tightly. “Why are you here?”

“Aw, Derek, how many times do I have to remind you I’m still just Kate?” Stiles felt like he wanted to dissolve into the walls as he watched Derek meet her predatory smile with a stony glare. “Anyway. The history department is holding a Halloween party next week and we haven’t seen each other in some time, so I figured I’d see if you were interested in joining."

Derek released a bark of harsh laughter that grated on Stiles’s nerves in a way he couldn’t quite describe. “You can’t be serious? Why would I go to anything with you after what you did?”

She gave him another predatory smile. “Just figured I’d see what options were open.” Then she turned to Stiles, looked him once over, and said in an unpleasantly suggestive tone, “Have fun with your office hours.”

Derek stared out after her with an unreadable expression on his face and the two sat in tense silence for several moments before Stiles stood and grabbed his bag. “Uh, unless you wanted to talk about anything else, I’m gonna go.” His voice was quiet as though he could shatter the air if he spoke too loudly.

“Yeah.” Was all Derek said.

Class on Monday was as uncomfortable as the first few weeks had been, and Derek staunchly refused to look at or call on Stiles. It made him want to sink in on himself and disappear, because at least if he wasn’t there he wouldn’t have to deal with the fact that Derek apparently didn’t want him to be there. As the rest of the week progressed, the pit that had developed in Stiles’s stomach during class only deepened until it morphed into a full blown black hole when Derek texted him Thursday night and told him he wasn’t having office hours the next day. It felt like a personal jab, since Derek didn’t send an announcement to the class. Even though he knew no one ever went to office hours, it was like Derek’s way of telling Stiles that everyone but he was welcome.

That Saturday was Halloween and Stiles felt more emotionally spent than he had in ages. He, Scott, and Allison were going to a Halloween party Lydia had invited them to at her apartment, but when he showed up at Scott’s place and found the couple dressed as Little Red and the Wolf the hole Stiles had managed to fill slightly with shots of pre-party rum reopened as he was reminded of Derek. He tried telling himself to buck up as he took another shot with Allison before heading out. They weren’t dating. They weren’t even friends as far as he was aware. He had no right to feel insulted or betrayed by Derek’s sudden shift in demeanor towards him, but he did.

Later that night and one or two shots past where he should have stopped, Stiles texted Derek. It was an innocent and coherent message, but he really should have left his phone at home.

Stiles: Did I do something wrong, Derek?

Of course he didn’t get a response and woke the next morning with a hangover and the shadow of regret and embarrassment hanging over him like a veil.

Stiles skipped discussion on Monday and didn’t bother texting Derek. He would know why he wasn’t there. If Stiles thought the weight and pain from Derek’s rejection of the nothing they currently had going on between them would dissipate he was oh so wrong. By Thursday night he was a verifiable mess, barely keeping himself distracted by attacking his senior thesis with a vengeance. On Friday morning he woke extra early to dress his very best and eat breakfast before stalking over to Derek’s office in the biology building.

 He barged into Derek’s office without knocking, and the TA jerked his head up in surprise. His face morphed into a strange combination of regret and uncertainty when he laid eyes on Stiles.

“What is your problem?” Stiles realized he was almost yelling, and shut the door behind him for all the good the thin barrier would do. “I didn’t do anything to you and then you just ignore me! Like I get we weren’t really friends, but we had a good something going. You have no right to ice me out like this.” His voice lost its force as he saw the stricken look in Derek’s eyes. “What?”

Derek looked firmly down at the hands in his lap as he replied with a small voice. “We did have a good something going.”

“So what’s the problem?” Stiles couldn’t keep the roughness out his voice.

“It was starting to be too good of a thing.” He looked up helplessly, but sighed when he saw how confused Stiles was. “I like you Stiles, but I’m not going to go there.”

“I-I like you too though.” This wasn’t the perfect, cute confession Stiles had been hoping to make once he and Derek would be allowed to date. “Is this about the rules?”

Derek released a huff of sarcastic laughter. “You could say that.” He didn’t continue though and Stiles gave him an exaggeratedly expectant look.

“Don’t leave me hanging, Derek.”

Sighing loudly, Derek explained. “Last year, when I was a senior, Professor Argent was a last year grad student, and was assistant teaching a French lecture I was in. She came onto me one day in office hours but I turned her down and before I could complain to the department, which I wouldn’t have, she tried playing it off to them like I was bribing her for grades. There was no proof either way, but the department chose to believe her, and they told me they wouldn’t report me to the honor council if I withdrew from the class.”

Silence engulfed them upon the confession and Stiles just stared at the pained expression on Derek’s face until it occurred to him that he should say something. “That’s awful. I’m sorry.”

Derek smiled sourly at him. “I was trying to keep this all under control, but when she came by last week I just felt like I was already starting to break the rules. I didn’t want you to keep pushing, so I shut you out. I’m sorry.”

Stiles’s chest felt like it wanted to burst and implode simultaneously. He was practically glowing knowing that Derek apparently liked him, but his heart also felt like it was being squeezed with the anticipation of rejection. “So you want me to stop coming to office hours.” He said, his voice crestfallen.

“No! I-I don’t think so.” Derek paused for a moment before continuing. “No I want you to keep coming.” He sighed before finishing, “This is going to suck.”

Stiles shot him an impish grin, hope swelling rapidly in his stomach. “Only for four more weeks until classes are over. TA’s don’t grade finals, so we’re going out as soon as you’ve graded my last phys assignment.” Stiles finished with a wink and felt a thrill shoot through his spine at the flush that tinged Derek’s cheeks. “I’ll see you on Monday, Derek.”

The next four weeks did in fact suck. If Stiles had thought Derek was irresistible before when he thought he didn’t have a chance, he was absolutely appetizing now and he woke up hard most mornings after dreaming about having various kinds of fun on Derek’s desk. Class was harder to tolerate than office hours because Derek would give him this special little private smile when he got an answer right (which was often) and Stiles would squirm in his chair as he tried to pretend it wasn’t making his heart flutter and his cheeks flush.

On the last week of office hours, Derek finally told Stiles why he studied wolves. His family owned a preserve near the town of Beacon Hills that they had contracted out to the government for land meant to reintroduce wolves to California. He’d grown up watching the wolves run through the preserve, naming the new pups with his sister, and watching his parents track their GPS tags on the computer. When he was 16, some idiotic college kids had started a fire too close to their house during the dry season and it had caught ablaze, with most of his family trapped inside. He and his sisters had been counseling at a sleepaway camp and had come home to a destroyed family and half-burnt preserve. The wolves had managed to escape the fire, and other than his sisters, they were all he had left. His research just sort of fell into place from there once he’d gotten to Berkeley.

They sat in silence for a while once Derek finished. Stiles knew from experience that platitudes like ‘I’m sorry’ only ever made people feel more pathetic but he also wasn’t sure what else he could say that wouldn’t. He wanted to thank Derek for trusting him with such personal information. He wanted to assure him that his family would be proud of what he was doing right now. None of it seemed appropriate.

“Did they catch the kids who started the fire?” His voice sounded too loud in the silence, even though he tried staying quiet.

“It took some time, but yeah. They weren’t having any luck for a while because any evidence they left behind had been burned, but one of the kids turned himself in a few months later and he named the friend he was with for a reduced sentence of arson instead of manslaughter.”

Stiles reached out to grip Derek’s hand in a comforting squeeze, and to his surprise, he didn’t pull away. It occurred to Stiles once he left Derek’s office half an hour later that that had been the first time they’d touched since meeting. His fingers tingled at the thought, and he smiled despite the sad events that had led to the contact.

Classes ended the next Thursday, and Stiles got a text from Derek that evening.

Derek: You kept tomorrow open right?

Stiles: Nope. I decided to get a jump start on my phys studying ;)

Derek: Funny.

Derek: I’ll pick you up at 8 :)

Stiles did not expect the Camaro that appeared in front of his apartment the next morning or the leather clad Derek that stepped out of it. Derek chuckled when he saw the look of disbelief on Stiles’s face.

“What?”

“You-you drive a sports car. And you wear leather. Why have I never seen that jacket before? Why have you been hiding how cool you are?”

“You mean you didn’t think your stuttering TA who couldn’t make eye contact was cool?” Derek shot back with a cheeky grin. “Get in. We’ve got a drive.”

The ride was peaceful and content. Derek talked a little, but Stiles’s voice was the predominant sound in the car most of the way. They reached the outskirts of Beacon Hills about two hours later and Derek turned off onto a side road that twisted through a pine forest before stopping in front of a large house with a beautiful front porch.

Stiles stared at it a few moments, before realization dawned on him. “This is the preserve. This is your house.”

Derek nodded. “It’s technically on preserve property, so the government rebuilt it for us. My older sister Laura lives here, and she oversees the wolves now. She’s not home right now though.”

“The wolves! Are we here to see the wolves?” Stiles practically leapt out of the car as Derek nodded and bounced impatiently as he took his sweet time to get out of the driver’s side. They walked hand in hand along a fenced off pathway used for visitors who wanted to see the wolves without disturbing them. About a mile down, Derek stopped abruptly and pointed down a hill to their left and following his finger Stiles could see a small pack of grey wolves dozing near a den. He stared at them in rapture, never having seen live wolves before, and only turned away when he felt Derek slip his arm around his waist and pull him close. It made his heart pound beautifully against his ribs and he shivered involuntarily at the fact that they were finally allowed to be together.

They stood holding each other close for a while, just watching the relaxed wolves before something occurred to Stiles and he couldn’t resist asking. “So you never told us on the first day of class. What’s your favorite part of the body?”

“If you had asked me that then, I would have said the spine.”

“And if I ask now?”

Derek blushed furiously and gave him an intimate smile that made Stiles shudder. “Any part of you.”

**Author's Note:**

> If you all like it, I'll write a counterpart from Derek's perspective! 
> 
> Comments always appreciated and come visit me on [tumblr](http://a-mountain-ash.tumblr.com/)!


End file.
